GB1582782A - Photocopier document transport system - Google Patents

Description

PATENT SPECIFICATION

( 11) 1 582 782 ( 21) Application No 26677/77 ( 22) Filed 24 June 1977 ( 19) ( 31) Convention Applicatiori No' 708 052 ( 32) Filed 23 July 1976 in ( 33) Unflited States of America (US) ( 44) Complete Specification published 14 Jan 1981 ( 51) INT CL 3 B 65 H 9/00 9/10 29/16 ( 52) index at acceptance B 8 R 401 471 535 561 572 582 584 601 671 681 AR 2 ( 54)' PHOTOCOPIER DOCUMENT TRANSPORT SYSTEM ( 71) We, AM INTERNATIONAL INC, a corporation organized under the laws of the State of Delawa-re, United States, of America, 6 f 1900 Avenue of the Stars', Los Angeles, California 90067, United States' of America, do hereby declare the invention, for which we pray that a patent' may be granted to us, and the method by which it is to be performed, to be particularly described in arid by the'

following statement:-

This' invention relates to photocopiers and more especially to document transport in photocopiers An important object of this, invention is the' elimination of register stops acting against the:

leading edge of documents to' be copied Prior art mechanisms employing Such stops have the undesirable characteristic of possibly damaging the forwatd edge of lightweight originals as they strike the stops Furthermore, such' stops will be imaged unless means.

are provided to retract them' during an exp'osure, Position sensors have beernf employed t'o bring sheets' to a stop position, with vafyin'g degrees of success.

The inventiori provides a photocopier' haing' a transparent document positioning table, first and second spaced belt guides positioned above said table, a belt: reeved ovef said guides with the bottom run: resting on said table and a return' run extending between: the tops of said guidegs, said belt forming and entranice nip' as it loops over said, first guide to the, table sutface;, inicluding a drive system for said belt to cause said belt to first move a sheet presented: to the efitlran'ce: nip to an exposure station of said tablle; to pause, and then resume moving fto initiate the exit of the sheet, comprising; a rotatable power driven shaft connected; f O said: belt to drive said belt'; means to seris Oe presentation Of the fead; e'dge of a sheet to said nip and to, initiate fotatib-n' of said power drivenfi shaft and the i 'tsulting belt drive motion in, response there-& t'o,; and 'nttrol meani for::

1 L assuming cbtritrbl of said: belt drive ihtioi: ft-romf saidi mnieans tf' init iate-rotatiori ini response to initial rotation of said power driven shaft; 2 continuing the drive motioft of the belt for a predetermined belt advancemn'e'iit across the table sufficient toh'a-ve transported 55 the sensed lead edge of a sheet from said nrip to a predetermined lead: edge position for exposure, and then stopping the drive at that position; and 3, reinstating drive motion of the belt 60 Subsequent to an exposure: sequence, for a further travel sufficient to have' transported a sheet off of the exposure station'.

One embodiment of the invention will now be described by way' of example with reference 65 to the accompanying drawings in which:

Figure'1 is a side elevation illustration of the principal operating components of a sheet feeder; Figure 2 is a plan view illuiistration of the 70 principal operating components of arin embodiment of an electrostatic copier table to utilize sheets delivered by' the' Figure 1 feeder;' Figure 3 is'a side elevation illustration of thecopier table; 75 Figure 4 is a schematic illustration of the combination of a feeder and utlization device of this invention; and Figure 5, is an electrical coritrol schedm'aticg The' sheet feeder is: represented in general 80 by the reference character 10 in the Figure 1 '.

The utilization device, Which is actually the glass support table of a photocopy' machirie; is indicated in general by' the referencet Character 12 in' both Figures 1; and 2 Docu 85 rnents from the feeder 10 are placed on the copier 12 by a feed device which operates over a measured distance' rather-than being Stopped by the arrival of the sheet at a' Stop device on the table 90

For the purpose of this descri-ptioin, the feeder 10 comprises t Wo' end druris 14 and 15 about Which ate reeved a series: of drive bflt1 f 6 A bell crank system operates a roller 18 & by mea/ns: of p'o We supplied ffo a solekoiid: 95 mrotof 20 to distend the belts whenfievetr a sheet is to be stripped from' a gt-'ack of dof/ rmeits plaetd' on' a refractable bedi 22 A sei'-, sr switich 23 dfetects thel pfesetice of a sheet:

oh' bed 22 Powef is Sgupplied to dri Ve: the bel'fs 100 C 9 t_ N Ltl P1,582,782 16 by means of a motor 24 operating through a belt 26 With the roller 18 lifted, the belts 16 are out of driving frictional contact with documents on the bed 22 In order to separate a top document from a stack, or a single document from table 22, the drive motor 24 activates the belts 16, and the solenoid 20 is activated to lower the roller 18 and force the belts against the top of the document The belt is brought into contact with the paper by this action and the frictional drag force on the document causes the document to move forward from the feeder 10 toward the photocopier 12.

As the document is fed from feeder 10, toward the photocopier 12, it is caused to strike the operating switch arm 28 of a sensitive switch 20 Switch 30, shown in the electrical schematic of Figure 5, stops operation of the feeder 10 and initiates operation of the conveyor portion of the photocopier 12.

Figures 2 and 3 illustrate the transport table of the photocopier 12.

Figures 2 and 3 can best be understood if compared with the schematic illustration of Figure 4 The object to be accomplished, is to slide the proffered document across a transparent table 32 to a predetermined fixed registration position without the use of stop devices to bring the document, whatever its length, to that registration position The lead edge of the document is to be positioned at the registration line and the tail end is permitted to extend the length of the document When the switch 30 is activated, a motor 34 is energized and is caused to drive a pulley 36 which in turn drives a main shaft 38 Shaft 38 is coupled to the pulley 36 by means of a slip clutch 40.

In commerical use, to provide operator protection if the cover is removed, clutch 40 on the output shaft of motor 34 The clutch drives a pulley which is coupled to pulley 36 by a belt 37 In that arrangement, shaft 38 is directly coupled to pulley 36.

Shaft 38 carries an idler roller or series of idler rollers 42 A second shaft 44 carries idler rollers 42 A The shafts 38 and 44 are coupled by a positive drive means such as chain 46 driven by a sprocket 48 and driving a sprocket 50.

A wide belt 52, preferably having a white exterior surface, is reeved around the idlers 42 and 42 A for guide support, but is keyed to the chain drive 46 by means of a tab 53 carried by the chain and riveted to one edge of the belt Hence, drive of the shaft 38 causes an exact keyed drive of the belt 52, through the edge connection and not by the usual roller drive This construction also prevents any tendency to run off the rollers As best seen in Figure 3, the belt 52 is allowed to sag and drag along the top surface of the transparent table bed 32 A roller 54 is an idler roller biased against the surface of belt 52 at a tangent point of the rollers 42 to form a nip therewith The two shafts and their rollers constitute a means for moving the drive pad in yielding contact along the table surface 32 from an entrance end adjacent the nip of the 70 belt and roller 54 to an exit end at the opposite end of table 32 where the belt pad loops around rollers 42 A and lifts away from the table surface The idler roller 54, forming a nip as it does with the belt 52, serves as a 75 means for accepting a document from feeder and inserting that sheet into the nip of the pad belt 52 and the surface of table 32 at the entrance end Therefore, when the switch 30, being a means for detecting the presence of a 80 document sheet at that nip, is activated, it provides a signal for a controller to cease operation of feeding and begin the placement of the delivered document sheet on table 32.

The controller is a very simplified electrical 85 circuit shown schematically in Figure 5.

In the illustrated embodiment of the device, the motor 34 is a continuously running motor which drives the system through the friction slip clutch 40 When a document signals its 90 presence by operating switch 30, the controller activates a transport solenoid 55 to retract a block 56 from the path of a rotating stop cam 58 carried by the shaft 38 With the block 56 interfering as shown in the Figure 4, 95 clutch 40 will slip and shaft 38 is stationary.

When the solenoid 55 causes block 56 to retract, then the shaft 38 can turn under the drive impetus of the motor 34 via the pulley 36 The metering of the travel of the document 100 being transported across table 32 is accomplished by means of a cam switch control shown generally in the area of reference numeral 60 in Figures 2 and 3 This control comprises generally a set of gears 62 and 64 105 having a fractional speed ratio In the arrangement shown the gear 64 rotates onefourth as rapidly as its drive gear 62 The smaller gear 62 is carried by shaft 38 A cam 66 has a flat surface as seen best in Figure 4, 110 which is used to operate switches 68 and 70.

The cooperation and function of the various switches will best be understood by reference to Figure 5 A function switch 72 is generic in its representation in that it may be 115 a manually operated button, a program operated switch, or a sensor which senses the presence of a document leaving the system.

It may be all three of these devices For the sake of illustration, assume switch 72 is an 120 operator controlled push-button A battery symbol 74 represents a source of low power control voltage When switch 72 is closed it powers a relay 76 which closes a self-holding lock circuit through switch 78 and a switch 125 79 which closes the circuit to the feeder solenoid 20 If a document is in position upon the bed 22, the switch 23 will be closed and the solenoid 20 will receive power through the switch 79, switch 23, and through the switch 130 1,582,782 30, which is used as a normally closed switch with respect to solenoid 20.

The relay 76 also closes switches 80 and 81 to provide power from source "G" for both the motors 24 and 34 However, the belt 52 does not begin operation because it is locked by the pawl 56.

When the solenoid 20 and the motor 24 begin operating under the activation of relay 76, a document sheet is fed from the feeder to the switch 30 When switch 30 is moved from the full-line position shown in the Figure 5 to the dotted outline position by the impact of a document, the power to relay 76 is broken, and the solenoid 20 and the mtor 24 cease to operate.

Also, the switch 80 opens, which as illustrated in Figure 5 and thus far described, would apparently cease operation of motor 34.

However, when the switch 30 moves to the dotted outline position, it places a relay 84 into operation and pulls in a holding circuit switch 85, and switches 86 and 87 Therefore, the switch 87 is closed substantially simultaneously with the opening of switch 80, and the motor 34 is kept in a power circuit although the motor 24 is inactivated.

When the relay 84 is activated as described, solenoid 55 is placed in circuit through the closed switch 68 of the cam switch contact 60.

Solenoid 55 then pulls the pawl 56 away from the stop cam 58 and allows the shaft 38 to begin to drive the drive pad belt 52 The sheet, having tripped the switch 30, which is the detector at the nip of the pad and table surface, moves onwardly into the nip, which is now dynamic, and is clamped between the surface of idler 54 and the moving surface of the belt 52 The sheet is then caused to move onto the table and begin to move with the frictional drag surface of the belt 52 on the table.

The first operation of the shaft 38 causes the cam 66 to close the normally open home switch 70 and keep relay 84 in an active circuit after the document has passed by and released the switch 30 The the four-to-one ratio of gear 62 and gear 64 will permit slightly over two revolutions of the rollers 42 before bringing the flat surface of the cam 66 into position to open the normally closed registration switch 68.

When switch 68 is opened, the solenoid 55 is deactivated and the pawl 56 is returned by spring action (not illustrated) to engage the stop cam 58 at the end of three revolutions and half the advance of the document on table 32 The diameter of the rollers 42 is approximately equal to the pitch diameter of the drive sprocket and is selected to transport sufficient of the belt 52 to cause a sheet entering the nip of the table to come to a specific registration position on the table and half at that position without any type of stop device acting against the document.

The document, after coming to rest, may be exposed by a photocopier device, and at the end of the exposure, whether by program control or light sensitive devices, a switch 90 is caused to close thereby reactivating sole 70 noid 55 and once again withdrawing pawl 56 to allow the shaft 38 to turn for one more revolution to bring the flat spot of the cam 66 into position wherein the home switch 70 is caused to open and deactivate relay 84 75 Deactivation of relay 84 opens switch 87 and brings the motor 34 to a halt.

The final turn of the shaft 38 will cause the document sheet in position upon table 32 to proceed off of the table into any receptacle or 80 further processing desired In the Figure 4 an exit turnaround device 92 is illustrated, being a particular application structure desired.

However, the document could proceed directly off of the table if the surrounding 85 structure so dictated In any event, the normal length of document will cause a tail portion of the document to remain engaged between table 32 and belt 52 under normal circumstances If only one sheet is being processed, 90 the operator or a processing device could grasp the sheet and pull it from the engaged position because the gripping action is very light.

However, this device was designed as a repetitive action copy machine to process an 95 entire stack of sheets and consequently, as long as switch 23 detects the presence of a document on the bed 22, the program will recycle to reinitiate operation of the processing system and thereafter cause sequential 100 repeat of the steps wherein the sheet feeder is caused to separate and forward one sheet from the holder, be detected at the nip, be driven on to the pad, partially ejected after the processing step and then recycled again as 105 long as documents remain to be processed.

Not illustrated, but being built into the circuit of the switch 23, is a program chip which causes a false end-of-exposure routine to close the switch 90 and eject the final 110 sheet from the machine by one last additional rotation of the cam 66.

Claims (3)

WHAT WE CLAIM IS:- 1 A photocopier having a transparent 115 document positioning table, first and second spaced belt guides positioned above said table, a belt reeved over said guides with the bottom run resting on said table and a return run extending between the tops of said guides, 120 said belt forming an entrance nip as it loops over said first guide to the table surface, including a drive system for said belt to cause said belt to first move a sheet presented to the 125 entrance nip to an exposure station on said table, to pause, and then resume moving to initiate exit of the sheet, comprising: a rotatable power driven shaft connected to said belt to drive said belt; 130 means to sense presentation of the lead edge of a sheet to said nip and to initiate rotation of said power driven shaft and the resulting belt drive motion in response thereto; and control means for:

1 assuming control of said belt drive motion from said means to initiate rotation in response to initial rotation of said power driven shaft; 2 continuing the drive motion of the belt for a predetermined belt advancement across the table sufficient to have transported the sensed lead: edge of a sheet from said nip to a predetermined lead edge position for exposure, and then stopping the drive at that position: and 3 ' reinstating drive motion of the belt subsequent to an exposure sequence, for a further travel sufficient to have transported a, sheet off of the exposure station.

2 A photocopier as set forth in claim 1 in which said control means includes, a switch cam and a plurality of switches riding said cam, said cam being in a driven relationship; to said power driven shaft such that' the circuit control cam rotates once while the power driven shaft rotates more than once:

a holding circuit for controlling rotation of said: power shaft, a first one of said switches reacting to initial shaft rotation to energize said holding circuit to keep said shaft in motion after a transported sheet passes said means to sense presentation of the lead edge;' a second one of said' switches and the cam cooperating to alter said holding circuit for stopping said shaft and the belt after a cam predetermined travel of the shaft and belt; and said cam being structured: such' that after reinititiation of drive motion of the belt, the first of said' switches is caused to deenergize the holding circuit upon' said cam turning to the end of its one rotation, whereby, a major fractional portion of the control cam-rotation may be employed to advance the belt and the sheet upon the table, arresting the latter with its leading edge at' said predetermined lead edge position, andl the' remaining minor fractional portion may' be employed to cause the belt drive to again cease after being' reni itiated.

3 A photocopier substantially as hereinv before described with reference to the accompanying drawings.

Agents for the Applicants:

LLOYD WISE, TREGEAR & CO.

Norman House, 105-109 Strand, London WC 2 R OAE.

Printed'for Her Majesty's Stationery Office by Burgess & Son (Abingdon), Ltd -1981.

Published at The Patent Office, 25 Southampton Buildings, London; WC 2 A l AY' from which' copies may be obtained.

1,582,782